American Journal of Electrical and Electronic Engineering
ISSN (Print): 2328-7365 ISSN (Online): 2328-7357 Website: http://www.sciepub.com/journal/ajeee Editor-in-chief: Naima kaabouch
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American Journal of Electrical and Electronic Engineering. 2016, 4(6), 157-163
DOI: 10.12691/ajeee-4-6-2
Open AccessArticle

Analysis of Transformer Loadings and Failure Rate in Onitsha Electricity Distribution Network

Hachimenum N. Amadi1, and Fabian I. Izuegbunam1

1Department of Electrical & Electronic Engineering, Federal University of Technology, Owerri, Nigeria

Pub. Date: December 22, 2016

Cite this paper:
Hachimenum N. Amadi and Fabian I. Izuegbunam. Analysis of Transformer Loadings and Failure Rate in Onitsha Electricity Distribution Network. American Journal of Electrical and Electronic Engineering. 2016; 4(6):157-163. doi: 10.12691/ajeee-4-6-2

Abstract

This study investigated transformer loadings and failure rate in the Onitsha Electricity Distribution Network by using the Electrical Transient Analysis Program (ETAP) software 12.6 and the Statistical Package for the Social Sciences (SPSS) software 16.0. Data collected over the period 2011-2015 on the distribution network were simulated on ETAP software using the Newton-Raphson (N-R) technique to determine the transformer loadings while responses to 350 copies of questionnaire distributed among the technical staff were statistically analysed on the SPSS software to ascertain the failure rate among transformers in the network. The findings of the study show that during the 5 years period covered by the study, the sampled substations recorded transformer average failure rate of 11.7 %. It was further revealed that besides insulation issues which accounted for 24.2% of all the failures, overload (22.5%) was the next major cause of transformer breakdowns in the distribution network. The study recommends installation of more transformer units, use of high quality transformers, balanced loading of the transformers and proactive inspection and maintenance program of transformers units within the network. The outcome of this work would help electricity utilities provide more reliable and cost effective services to customers.

Keywords:
distribution network electricity supply failures failure rate transformer failure transformer loading

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References:

[1]  Pasricha, A. (2015). “A Study into improving Transformer Loading Capability beyond Nameplate Rating”. Masters Theses. Missouri University of Science and Technology, Missouri.
 
[2]  Short, T. A. (2003). Electric Power Distribution Handbook. CRC Press.
 
[3]  Bartley, W.H. (1998). “An Analysis of Transformer Failures, Part 1 – 1988 through 1997.” Available at https://www.hsb.com/TheLocomotive/AnAnalysisOfTransformerFailuresPart1.aspx.
 
[4]  Vahidi, F and Tenbohlen, S. Statistical Failure Analysis of European Substation Transformers. Conference paper. November 2014. Available at: https:www.researchgate.net/publication/272088767.
 
[5]  Energy Efficiency and Renewable Energy Office (2013). Energy Conservation Program: Energy Conservation Standards for Distribution Transformers Rule. Available at: https://www.regulations.gov/document?D=EERE-2010-BT-STD-0048-0762.
 
[6]  Electrical India (2015). Case Studies of the Transformers Failure Analyses. Available at: http://www.electricalindia.in/blog/post/id/5692/case-studies-of-the-transformers-failure-analyses.
 
[7]  Bartley, W.H. (2003). Analysis of Transformer Failures. International Association of Engineering Insurers 36th Annual Conference – Stockholm.
 
[8]  Bartley, W.H. (2004). Investigating Transformer Failures. The Hartford Steam Boiler Inspection & Insurance Co., Harford.
 
[9]  Mirzai, M.; Gholami, A. and F. Aminifar (2006). Failures Analysis and Reliability Calculation for Power Transformers. Journal of Electrical Systems, 2-1, 1-12.
 
[10]  What is the effect of “Overload”? Available at: http//:www.hammondpowersolutions.com.
 
[11]  Hershey Energy Systems. Available at: http//:www.hersheyenergy.com.
 
[12]  McCarthy, J. (2010). Analysis of Transformer Ratings in a Wind Farm Environment. Dublin Institute of Technology, Dublin.
 
[13]  Efobi, K. and Anierobi, C. (2013). Urban Flooding and Vulnerability of Nigerian Cities: A Case Study of Awka and Onitsha in Anambra State, Nigeria. Journal of Law, Policy and Globalization, 19.
 
[14]  Tahir, M. “Intelligent Condition Assessment of Power Transformer Based on Data Mining Techniques” (2012). A Masters Thesis. University of Waterloo, Ontario, Canada.
 
[15]  Saad, F.A. M. (2011). Predicting Transformer End of Life using Transformer Thermal Life Simulation Technique. Masters Thesis. University Tun Hussein Onn, Malaysia.
 
[16]  Jadeja, K.V. (2011). Transformer Testing and Fault Finding. Available at: http://www.brighthubengineering.com/power-generation-distribution/126102-transformer-testing-and-fault-finding/.
 
[17]  IEEE C57.125-1991 “IEEE Guide for Failure Investigation, Documentation, and Analysis for Power Transformers and Shunt Reactors”, Transformer Committee of the IEEE Power Engineering Society, Copyright 1992 by the Institute of Electrical and Electronics Engineers, Inc..
 
[18]  Zhong, Q. (2011). Power Transformer End-of-Life Modelling: Linking Statistics with Physical Aging. Doctoral Thesis. The University of Manchester.
 
[19]  Mtetwa, S. and Cormack, R. (2006). “Addressing the Requirements of an Ageing Fleet of Transmission Transformers on the Eskom Transmission Network,” in CIGRE 2009 6th Southern Africa Regional Conference Cape Town, South Africa.
 
[20]  Chmura, L. (2014). Life-cycle assessment of high-voltage assets using statistical tools, PhD thesis. Technical University, Delft.
 
[21]  United Nations Human Settlements Programme (2012). Nigeria: Onitsha Urban Profile. UN-Habitat. Available at: http//:worldurbancampaign.org.